*{
    padding: 0;
    margin: 0;
    list-style: none;
    text-decoration: none;


}
.wrapper{
    margin:50px auto;
    width: 70%;

}
body{
    background: #ccc;

}
.wrapper .menu{
    height: 40px;
}
.menu li{
    min-width: 140px;
    background: linear-gradient(#0000FF,#00BFFF);/*径向渐变radial*/
    text-align:center;
}
.menu>li{
    float: left;
    position: relative;
}
.menu>li:first-child{
    border-radius: 5px 0 0 0;
}
.menu li:first-child  + .menu li:hover{
    border-radius: 5px 0 0 0;
}
.menu a{
    display: block;
    font-size:18px;
    line-height: 36px;
    border-left: 3px solid rgba(0, 0, 0, 0);
    color:#ffffff;
    padding: 0 25px;
    /*text-transform: uppercase;字母大写*/
}
.menu li:hover{
    background:linear-gradient(#00FF7F,	#F5FFFA)
} 
.menu li:hover>a{
    color:#000;
    border-left: 3px solid #000;
    
}
.sumenu{
    position: absolute;
    max-height: 0;
    left: 0;
    top:100%;
    z-index: 0;
    perspective: 400px;
}
.sumenu li{
    opacity: 0;
    transform-origin: 0 0;
    transform: rotate3d(0,1,0,90deg);
    transition:opacity 0.4s,transform 0.5s;
}
.menu>li:hover .sumenu li{
    opacity: 0.8;
    transform:rotate3d(0,0,0,0deg);

}
.menu>li:hover .sumenu{
    max-height: 1000px;
    z-index: 10;

}
.sumenu li:nth-child(1){
    transition-delay:0ms;
}
.sumenu li:nth-child(2){
    transition-delay:100ms;
}
.sumenu li:nth-child(3){
    transition-delay:200ms;
}
.sumenu li:nth-child(4){
    transition-delay:300ms;
}
.sumenu li:nth-child(5){
    transition-delay:400ms;
}